UNDERLYING CAUSES OF AF
The majority of AF is caused by other underlying heart problems or other conditions which can affect the heart such as high blood pressure (hypertension), obesity and sleep apnoea.
The thin walled top chambers of the heart become enlarged or damaged by these conditions leading to the abnormal, erratic electrical signals. Getting to the bottom of what heart and other health conditions have caused AF (and correctly managing them) is key to being able to understand the long term behaviour of AF and how successful the treatments will likely be. This is an important cornerstone in comprehensive management of AF.
Common Underlying Conditions that Cause and Worsen AF include:
heart valve conditions (in particular of the mitral valve)
coronary artery disease that has led to coronary stent, coronary bypass surgery or heart attack
congestive cardiac failure (from any cause)
cardiomyopathy (of any cause)
high blood pressure (hypertension)
obstructive sleep apnoea
Each person's genetic makeup also affects their likelihood of developing AF - it is well known that Europeans (caucasian race) have much higher rates of atrial fibrillation as they age compared with other ethnicities such as Asian or African American. In some families there can be a specific genetic abnormality that can cause multiple family members to develop AF at younger ages (20s to 40s) in the absence of other heart problems.
In some cases when no other obvious heart problem is present AF could be caused (or worsened) by thyroid problems or over-activity of vagal nerve inputs to the heart.